Concentrations In Drinking Water Research Articles

Transference factors as a tool for the estimation of arsenic milk concentration.

The Chaco Pampean Plain of central Argentina represents one of the largest regions with high levels of arsenic (As) in groundwater. The aim of this study was the assessment of a biotransference factor (BTF) as a tool for the estimation of As concentration in cow's milk from As drinking water concentration. Total As content in livestock drinking water, soil, forage, and milk was determined in farms located in an area of high As groundwater, in order to analyze the relation between As uptake and its transfer to milk. The concentrations of As in milk ranged from 0.5 to 8.0μg/L. From the results obtained, drinking water may be considered the main source of exposure to As, and the biotransference factor for milk ranges from 1.5 × 10(-5) to 4.3 × 10(-4). Therefore, BTF provides a simple tool for the estimation of arsenic levels in milk through the As livestock drinking water content.

Fluoride Concentration of Drinking-Water of Qom, Iran

Fluoride Concentration of Drinking-Water of Qom, Iran

Determination of 1,4-Dioxane in the Cape Fear River Watershed by Heated Purge-and-Trap Preconcentration and Gas Chromatography-Mass Spectrometry.

Recent U.S. Environmental Protection Agency data show that 1,4-dioxane is frequently detected in U.S. drinking water derived from both groundwater and surface water. 1,4-Dioxane is a likely human carcinogen, and an excess 10(-6) cancer risk is associated with a drinking water concentration of 0.35 μg/L. To support 1,4-dioxane occurrence investigations, source identification and exposure assessment, a rapid and sensitive analytical method capable of quantifying 1,4-dioxane over a wide concentration range in a broad spectrum of aqueous matrices was developed. The fully automated method is based on heated purge-and-trap preconcentration and gas chromatography/mass spectrometry with selected-ion storage and has a reporting limit of 0.15 μg/L. Quantification of 1,4-dioxane was accomplished by isotope dilution using mass-labeled 1,4-dioxane-d8 as internal standard. Matrix spikes yielded recoveries of 86-115% in drinking water, groundwater, surface water, and wastewater treatment plant (WWTP) effluent. Also, 1,3-dioxane can be distinguished from 1,4-dioxane. The method was applied to investigate 1,4-dioxane occurrence and sources in the Cape Fear River watershed of North Carolina. 1,4-Dioxane concentrations ranged from <0.15 μg/L in nonimpacted surface water to 436 μg/L downstream of a WWTP discharge. In WWTP effluent, 1,4-dioxane concentrations varied widely, with a range of 1.3-2.7 μg/L in one community and 105-1,405 μg/L in another. Discharges from three municipal WWTPs were primarily responsible for elevated 1,4-dioxane concentrations in the Cape Fear River watershed.

Carcinogenicity and chronic toxicity of hydrazine monohydrate in rats and mice by two-year drinking water treatment

The carcinogenicity and chronic toxicity of hydrazine monohydrate was examined by administrating hydrazine monohydrate in drinking water to groups of 50 F344/DuCrj rats and 50 Crj:BDF1 mice of both sexes for two years. The drinking water concentration of hydrazine monohydrate was 0, 20, 40 or 80 ppm (wt/wt) for male and female rats and male mice; and 0, 40, 80 or 160 ppm for female mice. Survival rates of each group of males and females rats and mice were similar to the respective controls, except female rats administered 80 ppm. Two-year administration of hydrazine monohydrate produced an increase in the incidences of hepatocellular adenomas and carcinomas in rats of both sexes along with hepatic foci. In mice, the incidences of hepatocellular adenomas and carcinomas were increased in females, and significantly increased incidences of hepatocellular adenomas in females administered 160 ppm were observed. Thus, hydrazine monohydrate is carcinogenic in two species, rats and mice. Additionally, non-neoplastic renal lesions in rats and mice and non-neoplastic nasal lesions in mice were observed.

Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations

Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 μg L(-1) were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations - indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As μg L(-1) in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations.

Reconstructing Historical VOC Concentrations in Drinking Water for Epidemiological Studies at a U.S. Military Base: Summary of Results.

A U.S. government health agency conducted epidemiological studies to evaluate whether exposures to drinking water contaminated with volatile organic compounds (VOC) at U.S. Marine Corps Base Camp Lejeune, North Carolina, were associated with increased health risks to children and adults. These health studies required knowledge of contaminant concentrations in drinking water—at monthly intervals—delivered to family housing, barracks, and other facilities within the study area. Because concentration data were limited or unavailable during much of the period of contamination (1950s–1985), the historical reconstruction process was used to quantify estimates of monthly mean contaminant-specific concentrations. This paper integrates many efforts, reports, and papers into a synthesis of the overall approach to, and results from, a drinking-water historical reconstruction study. Results show that at the Tarawa Terrace water treatment plant (WTP) reconstructed (simulated) tetrachloroethylene (PCE) concentrations reached a maximum monthly average value of 183 micrograms per liter (μg/L) compared to a one-time maximum measured value of 215 μg/L and exceeded the U.S. Environmental Protection Agency’s current maximum contaminant level (MCL) of 5 μg/L during the period November 1957–February 1987. At the Hadnot Point WTP, reconstructed trichloroethylene (TCE) concentrations reached a maximum monthly average value of 783 μg/L compared to a one-time maximum measured value of 1400 μg/L during the period August 1953–December 1984. The Hadnot Point WTP also provided contaminated drinking water to the Holcomb Boulevard housing area continuously prior to June 1972, when the Holcomb Boulevard WTP came on line (maximum reconstructed TCE concentration of 32 μg/L) and intermittently during the period June 1972–February 1985 (maximum reconstructed TCE concentration of 66 μg/L). Applying the historical reconstruction process to quantify contaminant-specific monthly drinking-water concentrations is advantageous for epidemiological studies when compared to using the classical exposed versus unexposed approach.

Elevated childhood exposure to arsenic despite reduced drinking water concentrations — A longitudinal cohort study in rural Bangladesh

ObjectivesThe aim of this study was to evaluate the massive efforts to lower water arsenic concentrations in Bangladesh. MethodsIn our large mother–child cohort in rural Matlab, we measured the arsenic concentrations (and other elements) in drinking water and evaluated the actual exposure (urinary arsenic), from early gestation to 10years of age (n=1017). ResultsMedian drinking water arsenic decreased from 23 (2002–2003) to <2μg/L (2013), and the fraction of wells exceeding the national standard (50μg/L) decreased from 58 to 27%. Still, some children had higher water arsenic at 10years than earlier. Installation of deeper wells (>50m) explained much of the lower water arsenic concentrations, but increased the manganese concentrations. The highest manganese concentrations (~900μg/L) appeared in 50–100m wells. Low arsenic and manganese concentrations (17% of the children) occurred mainly in >100m wells. The decrease in urinary arsenic concentrations over time was less apparent, from 82 to 58μg/L, indicating remaining sources of exposure, probably through food (mean 133μg/kg in rice). ConclusionDespite decreased water arsenic concentrations in rural Bangladesh, the children still have elevated exposure, largely from food. Considering the known risks of severe health effects in children, additional mitigation strategies are needed.

Arsenic and ultraviolet radiation exposure: melanoma in a New Mexico non-Hispanic white population.

Cases of cutaneous melanoma and controls were enrolled in a New Mexico population-based study; subjects were administered questionnaires concerning ultraviolet (UV) and inorganic arsenic (iAs) exposure. Historical iAs exposure was estimated. UV exposure estimates were also derived using geospatial methods. Drinking water samples were collected for iAs analysis. Blood samples were collected for DNA repair (Comet) and DNA repair gene polymorphism assays. Arsenic concentrations were determined in urine and toenail samples. UV exposures during the previous 90days did not vary significantly between cases and controls. Mean (±SD) current home iAs drinking water was not significantly different for cases and controls [3.98μg/L (±3.67) vs. 3.47μg/L (±2.40)]. iAs exposure showed no effect on DNA repair or association with melanoma. Results did not corroborate a previously reported association between toenail As and melanoma risk. Arsenic biomarkers in urine and toenail were highly significantly correlated with iAs in drinking water. A UV-DNA repair interaction for UV exposure over the previous 7-90days was shown; cases had higher DNA damage than controls at low UV values. This novel finding suggests that melanoma cases may be more sensitive to low-level UV exposure than are controls. A UV-APEX1 interaction was shown. Subjects with the homozygous rare APEX1 DNA repair gene allele had a higher risk of early melanoma diagnosis at low UV exposure compared with those with the homozygous wild type or the heterozygote. Notably, a UV-arsenic interaction on inhibition of DNA repair was not observed at iAs drinking water concentrations below 10ppb (μg/L).

Sources Of Manganese Exposure In Pregnant Women Living Near Banana Plantations In Costa Rica: Results From The Infant's Environmental Health Study (ISA) In Costa Rica

Introduction: Elevated manganese (Mn) in drinking water has been reported worldwide due to natural and anthropogenic contamination. Mancozeb is an ethylene-bis-dithiocarbamate (EBDC) fungicide containing 21% Mn. In Costa Rica, it is applied weekly by light aircraft on banana plantations. Within the context of the ISA study, we examined factors that explained Mn drinking water concentrations in communities located near banana plantations. Methods: We collected 126 drinking water samples from ISA participant's homes. In addition, we obtained repeated samples from 30 homes. We determined Mn concentrations in acidified samples using ICP-MS. Results: Median Mn concentration was 5.4 µg/L (interquartile range: 0.34 to 87 µg/L; range 0.4-1600 µg/L). For the repeated samples, the intraclass correlation coefficient was 0.95. Multiple regression analysis on log10-transformed Mn showed distance (in km) from a banana plantation was inversely associated with Mn water concentrations (β per 10-fold increase in exposure=-0.26, 95% CI: -0.41; -0.11). Distribution system predicted Mn concentrations, with significantly higher concentrations for banana farm and private wells (β=0.84, 95% CI: 0.36; 1.32) and lower concentrations for the National water supplier (β=-0.67, 95% CI: -1.06; -0.28) compared to miscellaneous systems. Immigrant communities, situated closest to the banana plantations, had higher concentrations of Mn in their drinking water compared to Costa Rican born participants. Conclusions: Mn concentrations were relatively high; several studies have shown negative associations between Mn in drinking water and children's cognition and behavior at concentrations similar to those observed in this study. Our findings suggest that both natural and anthropogenic sources contribute to elevated Mn in drinking water in these communities, possibly due to mancozeb spraying. Future studies should examine its possible contribution to elevated Mn in drinking water.

Fluoride Concentration in Community Water and Bottled Drinking Water: A Dilemma Today

Because of the potential for contamination of municipal water supplies, people appear to be turning to alternative sources for their pure drinking water. The present study analyzed the fluoride concentration in community water and bottled drinking water sold in Faridabad city. A comparative evaluation of fluoride content in community water supply and bottled drinking water was done using ion-selective electrode method. The community water samples were collected from six different areas (i.e. north zone, south zone, east zone, west zone and central zone) in the city from public health water supply taps while bottled drinking water samples were randomly picked from grocery shops or supermarkets. The fluoride concentration in the community water supply in this study ranges from 0.11 to 0.26 mg/L with mean fluoride concentration of 0.17 mg/L. The mean concentration of fluoride in bottled drinking water was 0.06 mg/L. The differences observed between mean of two water samples was statistically significant. The results obtained from the present study clearly state that the fluoride concentration was insufficient in community water supply from all the areas and also was deficient in bottled drinking water sold in Faridabad city. So, Alternative sources of fluorides should be supplemented for optimal dental benefits from the use of fluoride.

Does drinking water influence hospital-admitted sialolithiasis on an epidemiological level in Denmark?

ObjectivesSialolithiasis, or salivary stones, is not a rare disease of the major salivary glands. However, the aetiology and incidence remain largely unknown. Since sialoliths are comprised mainly of calcium phosphate...

Human adaptation to arsenic-rich environments.

Adaptation drives genomic changes; however, evidence of specific adaptations in humans remains limited. We found that inhabitants of the northern Argentinean Andes, an arid region where elevated arsenic concentrations in available drinking water is common, have unique arsenic metabolism, with efficient methylation and excretion of the major metabolite dimethylated arsenic and a less excretion of the highly toxic monomethylated metabolite. We genotyped women from this population for 4,301,332 single nucleotide polymorphisms (SNPs) and found a strong association between the AS3MT (arsenic [+3 oxidation state] methyltransferase) gene and mono- and dimethylated arsenic in urine, suggesting that AS3MT functions as the major gene for arsenic metabolism in humans. We found strong genetic differentiation around AS3MT in the Argentinean Andes population, compared with a highly related Peruvian population (FST = 0.014) from a region with much less environmental arsenic. Also, 13 of the 100 SNPs with the highest genome-wide Locus-Specific Branch Length occurred near AS3MT. In addition, our examination of extended haplotype homozygosity indicated a selective sweep of the Argentinean Andes population, in contrast to Peruvian and Colombian populations. Our data show that adaptation to tolerate the environmental stressor arsenic has likely driven an increase in the frequencies of protective variants of AS3MT, providing the first evidence of human adaptation to a toxic chemical.

Contenido en nitratos de aguas de consumo público españolas

ObjectiveTo determine nitrate concentrations in drinking water in a sample of Spanish cities. Material and methodsWe used ion chromatography to analyze the nitrate concentrations of public drinking water in 108 Spanish municipalities with more than 50,000 inhabitants (supplying 21,290,707 potential individuals). The samples were collected between January and April 2012. The total number of samples tested was 324. ResultsThe median nitrate concentration was 3.47mg/L (range: 0.38-66.76; interquartile range: 4.51). The water from 94% of the municipalities contained less than 15mg/L. The concentration was higher than 25mg/L in only 3 municipalities and was greater than 50mg/L in one. ConclusionsNitrate levels in most public drinking water supplies in municipalities inhabited by almost half of the Spanish population are below 15mg/L.

Preliminary Assessment of the Riverine Nitrogen Concentration and Load in an Agroforestry Basin in NW Spain

In this study, the concentrations and loads of different forms of nitrogen [nitrate nitrogen (NO3-N), total Kjeldahl nitrogen (TKN), and total nitrogen (TN)] in the headwater catchment of the Mero River (NW Spain) were analyzed. The TN concentrations were relatively low (mean: 2.57 mg L−1). Nitrate was the predominant form of N in the Mero catchment, accounting for 76.65 percent of the TN concentration. Measured NO3-N concentrations were always lower than the maximum allowed drinking water concentration. An annual TN load of 61.2 Mg was computed, representing an export of 0.94 Mg km−2 y−1, whereas annual exports NO3-N and TKN were of 0.79 and 0.15 Mg km−2 y−1, respectively.

Lung Cancer in Younger Adults Following Childhood Exposure to Low Concentrations of Arsenic in Water

Background: Arsenic drinking water concentrations &gt;100 µg/L are a known cause of cancer, but the risks at lower concentrations are unknown and controversial. With its unusual geology and good information on past exposure, northern Chile is one of the best places in the world to investigate the long-term impacts of arsenic. Methods: We performed a lung cancer case-control study in areas in northern Chile with a wide range of drinking water arsenic concentrations. Previously we reported evidence of high lung cancer odds ratios (OR) for arsenic concentrations &gt;100 µg/L. In this analysis, we calculated lung cancer ORs, adjusted for age, sex, and smoking, for those 92 cases and 288 population-based controls who had no known exposure above 100 µg/L at any point in their lives. Results: For exposures =40 years ago, lung cancer odds ratios (ORs) adjusted for age, sex, and smoking for increasing tertiles of arsenic exposure were 1.00, 1.43 (90% confidence interval, 0.82- 2.52), and 2.01 (1.14-3.52) (p-trend=0.02). Median arsenic water concentrations by tertile were 6.5, 23.0, and 58.6 µg/L. For subjects under age 65, corresponding ORs for exposures before age 25 were even higher. Adjustments for occupation, diet, and socioeconomic status had little impact on results. Conclusion: These findings provide rare new evidence that drinking water arsenic concentrations below 100 µg/L are associated with increased risks of lung cancer. These results also suggest that early-life exposure may cause marked increases in lung cancer in younger adults at arsenic water concentrations approaching those commonly found in the United States.

An upper-bound assessment of the benefits of reducing perchlorate in drinking water.

The Environmental Protection Agency plans to issue new federal regulations to limit drinking water concentrations of perchlorate, which occurs naturally and results from the combustion of rocket fuel. This article presents an upper-bound estimate of the potential benefits of alternative maximum contaminant levels for perchlorate in drinking water. The results suggest that the economic benefits of reducing perchlorate concentrations in drinking water are likely to be low, i.e., under $2.9 million per year nationally, for several reasons. First, the prevalence of detectable perchlorate in public drinking water systems is low. Second, the population especially sensitive to effects of perchlorate, pregnant women who are moderately iodide deficient, represents a minority of all pregnant women. Third, and perhaps most importantly, reducing exposure to perchlorate in drinking water is a relatively ineffective way of increasing iodide uptake, a crucial step linking perchlorate to health effects of concern.

Arsenic contamination in groundwater system of Viterbo area (Central Italy)

In the last years the presence of arsenic in groundwater became an urgent environmental issue. The As maximum concentration indrinking water has been changed from 50 μg/l to 10 μg/l, mainly due the effect observed on populations exposed to drinking waterrich in arsenic. Since many springs and wells of the Cimino-Vicano area exceeds the limits provided by Council Directive 98/83/EC,arsenic has become the most urgent issue of local governments bodies. The aim of this paper is to investigate about the presence of thiselement in groundwater and to contribute understanding of the behaviour of this in aquatic environment. In this project have beenanalyzed 44 waters samples, with temperatures ranging from 15° C to 62° C, and they have been compared with data obtainedfrom paper of Sappa et al., 2014, relative to water supply network. The results show that the predominant specie of As inagricultural and thermal water in reducing conditions is arsenite As (III) while the predominant specie present in drinking water inoxidant conditions is arsenate As (V).

On the toxicity of kynurenic acid in vivo and in vitro

BackgroundKynurenic acid (KYNA), a tryptophan metabolite is an antagonist of ionotropic glutamate receptors and alpha-7 nicotinic receptor. Moreover, it is an agonist of G-protein receptor GPR35. Its neuroprotective, anticonvulsant, anti-inflammatory and antioxidant activity was documented. KYNA is present in food and herbal medicines. However, the data on effects induced by a long-lasting treatment with KYNA is lacking. The aim of the study was the assessment of toxicity of a prolonged administration of KYNA in rodents. The cytotoxicity of KYNA in vitro was also examined. MethodsAdult mice and rats were used. KYNA was administered in the drinking water in concentrations of 25 or 250mg/L for 3–21 days. The following cells were cultured in an in vitro study: mouse fibroblast (NIH/3T3), green monkey kidney cells and primary chick embryo cells (CECC). Cell viability was determined with methyl thiazol tetrazolium reduction assay, neutral red uptake assay and lactate dehydrogenase leakage assay. ResultsKYNA affected neither body gain nor body composition. Blood counts were also unaffected. The viability of cells in the culture was lowered at high millimolar concentrations of KYNA. An elevated viability of GMK and CECC cells was detected in the presence of KYNA in micromolar concentrations. ConclusionsThe obtained results showed that a long-term application of KYNA in the drinking water is well-tolerated by rodents. No evidence of a toxic response was recorded. Achieved results indicate that diets containing a high amount of KYNA or enriched with KYNA should not cause any risk to the human health.

Radon and radium concentration in water from North-West of Romania and the estimated doses.

In the present study, the measurements of radon were carried out using the LUK-VR system based on radon gas measurements with Lucas cells. The radium concentration in water was determined, with the same device, immediately after was established the radon equilibrium with radium. The results presented here are from a survey carried out in the N-W region of Transylvania (Romania) in which were investigated the radon concentrations in natural (spring, well and surface) and drinking (tap) waters. The results showed radon concentrations within the range of 0.4-187.3 Bq l(-1) with an average value of 15.9 Bq l(-1) whereas radium concentration varied between 0.05 and 0.825 Bq l(-1) with an average value of 0.087 Bq l(-1) for all types of water covered within this survey. The corresponding annual effective ingestion dose due to radon and radium from water was determined from drinking water used by the population inhabiting the area.

Removal of Heavy Metal Ions from Industrial Waste Water Using Metallic Nanoparticles as Adsorbents

Water pollution is a major concern for the Government of India and other countries in recent years which arise due to the rapid industrialization. This rapid industrialization is leading to an ever-increasing use of various toxic chemicals. Most of the toxic chemicals contain heavy metals such as As, Cr, Cd, Cu, Zn, Fe, and Ni which are considered as hazardous pollutants. Disposal of these pollutants in the water streams causes serious environmental problems. Adsorption is an economic and comparatively effective process for the removal of heavy metals from wastewater streams. To achieve large surface area for adsorption, small size particle with high porosity are required to be developed. Today's era is focusing towards nanotechnology which is leading towards the use of nano-size materials. The demand for large adsorption capacity can only be met by nanoparticles as adsorbents. To reduce their concentration in drinking water, different Nanosized Metal Oxides (NMOs) were tested as adsorbents. The copper (II) oxide nanoparticles, in the present study, were prepared by precipitation method and characterised by SEM, XRD and FTIR techniques. The as synthesised nanooxide was found to have crystallite size in the range of 10–30 nm and the shape was found to be spherical. Systematic adsorption experiments were undertaken for the following two process parameters i.e., time of contact for different initial concentration and variation of adsorbent dosage to find out the efficiency of copper (II) oxide nanoparticles towards adsorption of zinc. The adsorption capacity as well as removal efficiency of zinc using Cu(II)O were calculated.